1. Field of the Invention
The present invention relates to an elevator system having an atmospheric pressure control unit to control the pressure in an elevator car during movement up and down.
2. Description of the Related Art
As elevators have been operated at superhigh speeds in high-rise buildings in recent years, a change in the atmospheric pressure in an elevator car during ascent and descent is not ignored. If the pressure in an elevator car is largely changed, it causes discomfort in the passengers' ears and impairs the riding comfort.
To lighten the influence of the pressure change in an elevator car, it has been considered to provide an atmospheric pressure control unit to keep the pressure in the car optimum during movement up and down. (For example, Published Japanese Patent No. 10-87189) The pressure control unit dissolves the discomfort caused by the pressure change, and passengers can use an elevator comfortably. Such a new technology is required in a future superhigh-speed elevator at a speed of 1000 m/min and an ascent/descent stroke of 400 m.
An elevator system is required to take an immediate and appropriate measure to ensure the safety of passengers when any abnormal condition occurs, for example, when a trouble occurs in an elevator car and the car fails to move normally, or an abnormal condition occurs in the elevator itself. A trouble in the above-mentioned pressure control unit is also included in such accidental cases. Particularly, a car of a superhigh-speed elevator is highly airtight, and if a trouble occurs in the air pressure unit serving also as a ventilator, it is important to ensure ventilation in the car.
In a conventional elevator system, safety measures are not established for troubles in a pressure control unit and the elevator itself.